Commodore Plus 4 - Page 103

The
Char
Command
This program draws a curve based on the sine function. Type NEW
and hit RETURN . Remember to hit the RETURN key after each
line, then type RUN.
10 COLOR 0.1
20 COLOR 1,2
30 GRAPHIC 1,1
40 LOCATE 0,100
50 FOR X=l TO 319
60 Y = INT (100 + 99 *SIN(X/20))
70 DRAW 1 TO X,Y
80
NEXT X
90 FOR L=l TO 5000
100 NEXT L
110 GRAPHIC 0
Don't type NEW after RUNning the last program. To plot the program
differently, change line 70 to:
70DRAW1.X, Y
This program plots Ihe same curve using points instead of lines.
Graphs are more easily understood and useful if you label them. You
can use the CHAR command to mix text right into a high resolution
drawing. For instance, the statement CHAR 1,0,5,"HELLO" puts the
word HELLO into the sixth row at the left edge of the screen. The first
number after the word CHAR is either 1 (for draw) or 0 (for erase). The
next two numbers are the column and row where the text appears.
Leave the last two programs in the computer: don't type NEW. Add
these lines
95